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Proceedings Paper

Laser-generated ultrasound for high-precision cutting of tissue-mimicking gels (Conference Presentation)
Author(s): Taehwa Lee; Wei Luo; Qiaochu Li; L. Jay Guo

Paper Abstract

Laser-generated focused ultrasound has shown great promise in precisely treating cells and tissues by producing controlled micro-cavitation within the acoustic focal volume (<100 um). However, the previous demonstration used cells and tissues cultured on glass substrates. The glass substrates were found to be critical to cavitation, because ultrasound amplitude doubles due to the reflection from the substrate, thus allowing for reaching pressure amplitude to cavitation threshold. In other words, without the sound reflecting substrate, pressure amplitude may not be strong enough to create cavitation, thus limiting its application to only cultured biomaterials on the rigid substrates.

By using laser-generated focused ultrasound without relying on sound-reflecting substrates, we demonstrate free-field cavitation in water and its application to high-precision cutting of tissue-mimicking gels. In the absence of a rigid boundary, strong pressure for cavitation was enabled by recently optimized photoacoustic lens with increased focal gain (>30 MPa, negative pressure amplitude). By moving cavitation spots along pre-defined paths through a motorized stage, tissue-mimicking gels of different elastic moduli were cut into different shapes (rectangle, triangle, and circle), leaving behind the same shape of holes, whose sizes are less than 1 mm. The cut line width is estimated to be less than 50 um (corresponding to localized cavitation region), allowing for accurate cutting. This novel approach could open new possibility for in-vivo treatment of diseased tissues in a high-precision manner (i.e., high-precision invisible sonic scalpel).

Paper Details

Date Published: 24 April 2017
PDF: 1 pages
Proc. SPIE 10064, Photons Plus Ultrasound: Imaging and Sensing 2017, 1006421 (24 April 2017);
Show Author Affiliations
Taehwa Lee, Univ. of Michigan (United States)
Wei Luo, Univ. of Michigan (United States)
Huazhong Univ. of Science and Technology (China)
Qiaochu Li, Univ. of Michigan (United States)
L. Jay Guo, Univ. of Michigan (United States)

Published in SPIE Proceedings Vol. 10064:
Photons Plus Ultrasound: Imaging and Sensing 2017
Alexander A. Oraevsky; Lihong V. Wang, Editor(s)

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